Copolymerization of acrylonitrile and another unsaturated monomer in the presence ofpreformed interpolymer



United States Patent COPOLYMERIZATION or ACRYLONITRILE AND ANOTHERUNSATURATED MONOMER IN THE No Drawing. Application February 3, 1954Serial No. 408,012

12 Claims. (Cl. 260-455) This invention relates to modifiedpolyacrylonitriles' and to a process for their preparation.

This application is a continuation-in-part of my copending applicationsSerial No. 279,210, filed March 28, 1952 (now abandoned) and Serial No.316,060, filed October 21, 1952 (now abandoned).

In copending application Serial No. 164,854, filed May 27, 1950 (nowUnited States Patent No. 2,649,434, dated August 18, 1953) of Coover andDickey, it is shown that valuable polymer products can be obtained bypolymerizing acrylonitrile in the presence of preformed livehomopolymers of various unsaturated monomeric compounds, i. e.homopolymers which have not been separated from their polymerizationreaction mixtures, the acrylonitrile being then added to the mixture andthe polymerization continued to Completion. In copending applicationSerial No. 198,761 .filed December 1, 1950 (now United States Patent,No. 2,620,434, dated December 2, 1952) of Coover and Dickey, it isshown that: still othervaluable polymer products can be obtainedibypolymerizing acrylonitrile'in the: presence of .dead homopolymers andcopolymers of various unsaturated monomeric compounds, i. e.-polymerswhich have beenfirst isolated from their polymerization reactionmixtures and then acrylonitrile polymerized in the presence of theisolated polymer. In copending application Serial No. 198,762, filedDecember 1, 1950 (now United States Patent No. 2,657,191, dated October27, '1

1953) of Coover and Dickey, it is shown that other valuable polymerproducts can be obtained bypolymerizing acrylonitrile in the presence oflive interpolymers of various unsaturated monomeric compounds. Theprocesses used in the above applications are all concerned with thehomopolymerization of acrylonitrile in the presence of a preformedpolymer. Modified acrylonitrile polymers of this kind can be spuninto'fibers having greatly increased moisture absorption" anddyeability. Such fibers have, in addition, all the other desirablephysical properties exhibited by fibers produced from straightpolyacrylonitrile. They can readily be .dry or wet spun into highstrength fibers exhibiting various degrees of extensibility dependingupon the extent to which and the conditions under which the fibers weredrafted. For example, if the fibers are drafted over a range of 100-600percent and relaxed, the extensibility of the yarn will increasesomething on the order of 30 percent at low drafts down to 17 or 18percent at high drafts. Under the maximum drafting and relaxingconditions, it is not possible with these polymers to obtain fibershaving extensibility exceeding 30 percent and still retaimng tenacity inthe order of 2.5-3.0 g. per denier. However, from a textile point ofview, it would be highly desirable to be able to produce fibers havingnot only the outstanding properties such as moisture absorption, dyeaffinity and other valuable physical properties, but also anextensibility in the range of 30-50 percent.

Polymers prepared according to the processes of the above pendingapplications can be dissolved in common I 2,838,470 Patented June 10,1958 "ice set up in, theform of agel. However, from, a production pointof view it is highly desirable tobe able, to prepare dopes containinghigher concentrations of polymer, 1. e. 25percent or higher, becausesuch higher solids dopes make it possible to produce fibers at a muchfaster rate. Furthermore, higher solids solutions would be morepractical in that less solvent is required per pound of polymer; alsothe actual spinning costs are lessjin that iess solvent perjpound ofspun fiber has to be extracted in the wet spinning process orvolatilized in a dry spinning process. Another consideration is thatinwet or dry spinning processes, especially for high solids dopes, it isnecessary to filter the solutionfree ofextraneous materials and gelledparticles that may be present so that they will not, plug the s'pinneretTo facilitate-filtration, it is necessary to maintain solutiontemperaturessufiiciently high to dissolve completely the polymer andgive a homogeneous solution. However, it is well known that solutions ofacrylonitrile polymers discolor on heating,

solids content substantially greater than 25 percent which at the sametimecbuld befiltered at relatively low temperatures,thereby making itpossible to produce yarns at lower costs and having greatly improvedcolor.-

I have now made thejunusual and valuable discovery that whensmallamounts of one or more modifying unsaturated monomers arecopolymerizedwith acrylonitrile in the presence of cer'tain.livecopolymers, i.efcopolymers which have not been separated from theirpolymerization'reaction mixtures, the products obtained show not-onlygood moisture absorption and dyeability, but other greatly improvedproperties which are especially valuable for textile purposes. foundthat polymers prepared in accordance with the invention are rnuch morereadily soluble in acrylonitrile polymer solvents, and their solutionsor dopes canbe made up to contain from 25-40 percent polymer solids, andthat such dopes remain clear, flowable and filterable without anygelling at temperatures below 100 C., in contrast to hitherto known highsolids acrylonitrile polymer dopes which still exhibit gelling effectsat temperatures substantially above 100 C., for example 100 C. and evenhigher, and result in discolored fiber and yarn. Furthermore, when thepolymers of the invention are spun either by dry spinning. or wetspinning processes, the fibers obtained can be more readily drafted andexhibit greatly improved extensibility for any given tenacity, i. e inthe range-of 40-50 percent. It is, accordingly, an objectof theinvention to provide a new class'of modified acrylonitrile polymers orcompositions. Another object is to provide a processior preparing thesenew polymers. Still another object is solids content of from about 25-40percent, based onthe total weight of the solution.- A further object isto provide improved 'fibers' from these compositions andtrom solutionsthereof. Other objects will become-apparent hereinafter. Y

In accordance with the invention, I preparemy new compositions orpolymers by subjecting to polymerizing conditions a dispersion ofitromjto parts by weight of a mixture comprising from 85.0 to 99.5 percent byweight of acrylonitrile and from 15 .0 to 0.5 percent by For example, we7 haveuseful as fiber-forming materials.

3 weight of one or more other different monoethylenically unsaturated,polymerizable compound containing a group, or more especially a group,in the presence of from 95 to 5 parts by weight of a live modifyingbinary copolymer obtained by co- ,polymerim'ng from 1 to 99%, butpreferably from 5 to 95%, by weight of a monomer selected from the groupconsisting of acrylamides, maleamides, fumaramides,

itaconamides, citraconamides, maleamates, fumaramates, itaconamates,citraconamates, acrylates and vinyl car- -boxylic esters, and from 99 to1%, but preferably from 95 to 5%, by weight of another different monomerselected from the above group of acrylamides, maleamides, fumaramides,etc. or acrylonitrile, until from about 70% to substantially 100% of themonomers present have been generally similar resinous compositions is toemploy a' -reverse" process, i. e. wherein from 5 to 95 parts by weightof a mixture comprising from 85.0 to 99.5%

by weight of acrylonitrile and from 15.0 to 0.5% by weight of one ormore other different monoethylenically unsaturated, polymerizablecompounds containing a --CH==C= group, is first substantially completelypolymerized to a live copolymer, and then without separating thecopolymer from its polymerization reaction .mixture, adding to thereaction mixture from 95 to 5 parts by weight of a mixture consisting offrom 1 to 99%, but preferably from 5 to 95%, by weight of a monomerselected from the above mentioned group of acrylamides, maleamides,fumaramides, itaconamides, citraconamides,

maleamates, fumaramates, itaconamates, citraconamates,

acrylates and vinyl carboxylic esters and from 99 to 1,

but preferably from 95 to 5, percent by weight of a different monomerselected from the above group of acrylamides, maleamides, fumaramides,etc., or acrylonitrile,

and continuing the polymerization until from 70% to substantially 100%of the added monomers are substantially polymerized.

The acrylamides provide modifying polymers which are especially usefulin practicing my invention. Those of my new compositions which containfrom 60 to 95 percent by weight. of acrylontrile have been found to beespecially However, all of my compositions in the 5 to 95 percent rangeof acrylonitrile content are compatible with each other, withpolyacrylonitrile and with other acrylonitrile polymers containing 85percent or more by weight of acrylonitrile, in all proportions, but themost useful mixtures comprise from 5 to 95 parts by weight of one ormore of the polymers of the invention with from 95 to 5 parts by weightof 4 alkyl group containing from 1 to 4 carbon atoms (e. g. methyl,ethyl, propyl, isopropyl, butyl, isobutyl, etc. groups) and R representsa hydrogen atom or a methyl group. Typical acrylamides includeacrylamide, N- methyl acrylamide, N-ethyl acrylamide, N-isopropylacrylamide, N-n-butyl acrylamide, methacrylamide, N- methylmethacrylamide, N-ethyl methacrylamide, N-isopropyl methacrylamide,N,N-dimethyl acrylamide, N,N- diethyl acrylamide, =N,N-dimethylmethacrylamide, etc.

As maleamides, -I can advantageously use those represented by thefollowing general formula: IV I oH-(i-N-Iu H-ClII-R| l R wherein R and Rare above defined. Typical maleamides include maleamide, N-methylmaleamide, N-ethyl maleamide, N-propyl maleamide, N-isopropyl maleamide,N-n butyl maleamide, N,N'-dimethyl maleamide, N,N"diethyl maleamide,N,N-di-n-butyl maleamide, N-methyl-N'- ethyl maleamide, N,N-tetramethylmaleamide, N,N'- tetraethyl maleamide, N,N-dirnethyl-N',N'-diethylmaleamide, etc.

As fumaramides, 1 can advantageously use those represented by thefollowing general formula: V 0 R OH-("J-dI-R. RiN-C- ("3H reprewherein Rand R are as above defined. Typical itaconamides include itaconamide,N-methyl itaconamide, N- ethyl itaconamide, N-n-butyl itaconamide,N,N'-dimethyl itaconamide, N,N-diethyl itaconamide, the N,N-butylitac'onamides, N,N'-tetramethyl itaconamide, etc.

As citraconamides I can advantageously use those represented by thefollowing general formula:

wherein R and R are as above defined. Typical citraconamides includecitraconamide, N-methy-l citraconamide, N-ethyl citraconamide, N-n-butylcitraconamide, N,N'-dimethyl citraconamide, N,N'-diethyl citraconamide,the N,N'-butyl citraconamides, N,N-tctramethyl citraconamide, etc.

The maleamates whose polymers I can advantageously use comprise thoserepresented by the following general formula:

VIII

CH-C-N-Rt i 15 wherein R and R are as above defined and R represents analkyl group containing from 1 to 41 carbon atoms.

Typical maleamates include methyl maleamate, ethyl maleamate, propylmaleamate, n-butyl maleamate, N- methyl methyl maleamate, N-ethyl methylmaleam-ate, the N-butyl methyl maleamates, the N-methyl butylmaleamates, N-dirnethyl methyl maleamate, N-dimethyl ethyl maleamate,N-dimethyl n-butyl maleamate, the N-dibutyl methyl maleamates, etc.

As fumaramates, I can advantageously use those repr sented by thefollowing general formula:

IX H

H=O'-O R,

wherein R, R and R are as above define-d. Typical fumaramates includemethyl fumaramate, ethyl fumaramate, propyl fumaramate, n-butylfumaramate, N-methyl methyl fumaramate, N-methyl ethyl fumaramate, theN- methyl butyl fumaramates, N-dimethyl methyl fumaramate, N-dimethylethyl fumaramate, N-dimethyl n-butyl furnaramate, the N-dibutyl methylfumaramates, etc.

As itaconamates, I can advantageously use those represented by thefollowing general vformulas:

wherein R, R and R are as above defined. Typical itaconamates includemethyl itaconamate, ethyl itaconamate, propyl itaconamate, the butylitaconamates, N-methyl methyl itaconamate, N-methyl ethyl itaconamate,N- methyl propyl itaconamate, N-methyl n-butylitaconam-ate, N-dimethylmethyl itaconamate, N-dimethyl ethyl itaconamate, N-dimethyl n butylitaconamate, the N-dibutyl methyl itaconamate, etc.

As citraconamates, I can advantageously use those represented by thefollowing general formulas:

wherein R, R and R are as above defined. Typical citraconamates includemethyl citraconamate, ethyl citraconamate, propyl citnaconamate, thebutyl citraconamates, N-methyl methyl citraconamate, N-methylethylcitraconamate, N-methyl propyl citraconamate, N-methyl nbutylcitraconamate, N-dimethyl methyl citraconamate, N-dimethyl ethyl citraconamate, N-dimethyl n-butyl citraconamate, the 'N-dibutyl methylcitraconamates, etc.

The acrylates whose polymers I can advantageously use comprise thoserepresented by the following general formula:

XIV V o cHi=o- H -0 R,

wherein R and R are as above defined. Typical esters 6 include methylacrylate, ethyl acrylate, propyl acrylate, -11- butyl acrylate, isobutylacrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate,the butyl methacrylates, etc.

As vinyl carboxylic esters I can advantageously use those represented bythe following general formula:

wherein R represents an alkyl group containing from 1 to 3 carbon atoms.Typical esters include vinyl formate,

vinyl acetate, vinyl propionate, vinyl butyrate, etc.

The monoethylenically unsaturated, polymerizable organic compoundsrepresented by Formulas I and IIabove include the compounds representedby Formulas III to XV, in addition to other monomeric compounds comingwithin the scope thereof, such as styrene, a-methylstyrene,p-acetaminostyrene, or-acetoxystyrene, vinyl ether, isopropenyl methylketone, ethyl isopropenyl ketone, methyl vinyl ketone, ethyl vinylketone, dimethyl maleate, diethyl maleate, diisopropyl maleate, dimethylfumarate, diethyl fumarate, diisopropyl fumarate, acrylic. acid,methacrylic acid, fumaronitrile, methacrylonitrile, N-vinyl phthalimide,vinyl sulfonamide, ethylene, isobutylene, etc.

Advantageously, the polymerizations are carriedflout in aqueous medium,although other reaction media 'such as organic solvents can be employed.The term dispersion herein is intended to include both true solutionsand emulsions in' aqueous or nonaqueous media. For example, apolymerization medium consisting of aqueous acetone or other aqueoussolvent can be-used. Thepolymerizations can be accelerated by heat, byactinic light such as ultraviolet light and by the use of well-knownpolymerization catalysts. Such catalysts are commonly used in the art ofpolymerization, and,our invention is not to be limited to any particularcatalyst material. Catalysts which have been found to be especiallyuseful comprise the peroxides (e. g. benzoyl peroxide, acetyl peroxide,acetyl benzoyl peroxide, lauryl peroxide, oleoyl peroxide, tria-cetoneperoxide, urea peroxide, t-butyl hydroperoxide, alkyl percar bonates,etc.), hydrogen peroxide, perborates (e. g. alkali metal perborates,such as those of sodium and potassium, etc.), persulfates' (e. g. alkalimetal persulfate ammonium persulfate, 'etc.).

Other catalysts such as the ketazines, azines, etc. can be' used. Thequantity of catalyst used can be varied, depending on the monomer,amount of diluent, etc. Sufficient catalyst can be used tohomopolymerize the ethenoid monomer selected from those represented bythe above general formulas and the monomericarcylonitrile, or an amountof catalyst suflicient to polymerize only the ethenoid monomer can beused, and additional catalyst can be added with the acrylonitrilemonomer to complete the polymerization. The catalyst added along withacrylonitrile may be the same catalyst that was used to polymerize theother ethenoid monomer. I have found that it is especially advantageousto use an amount of catalyst sufficient to'polymerize only the firstmonomer, and then upon addition of the acrylonitrile to add a furtheramount of catalyst at that time. -This procedure provides a readiermeans for regulating the molecular weight distribution of the polymercomposition.

The temperatures at which the process of my invention can be carried outvary from ordinary room temperature to the reflux temperature of thereaction mixture. Generally, a temperatureof from 25 to 75 C. issufficient.

If desired, emulsifying agents can be added to the reaction mixture todistribute uniformly the reactants throughout the reaction medium.Typical emulsifying agents include the alkali metal salts of certainalkyl acid sulfates (e. g. sodium laury sulfate), akali metal salts ofaromatic sulfonic acids (sodium isobutyl naphthalenesulfonate), alkalimetal or amine addition salts of sulfosuccinic acid esters, alkali metalsalts of fat-ty acids con- 7 taining from 12 to 20 carbon atoms,sulfonated fatty acid amides, alkalimetal salts of alkane sulfonicacids, sulfonated ethers (e. g. aryloxy polyalkylene ether sulfonates,such as Triton 720), etc.

The polymerization can be carried out in the presence of chainregulators, such as hexyl, octyl, lauryl, dodecyl, myristyl mercaptans,etc., which impart improved solubility properties to the polymercompositions. If desired, reducing agents such as alkali metalbisulfites (e. g. potassium, sodium, etc. bisulfites) can be added toreduce the time required for the polymerization to be effected.

Instead of using an aqueous medium in the polymerizations, it is alsopossible to use organic solvents such as acetonitrile, aromatichydrocarbons such as benzene, jtoluene, etc., liquid alkanes such asn-heptane, etc., aliphatic ethers, acetone, etc. Organic solvents whichare water-soluble can also be used with water in the polymerizations.The term dispersion is intended to include both true solutions andemulsions.

The polymerizations can also be carried out in a continuous manner,especially in. the second step of polymerization, i. e. wherein theacrylonitrile and the other polymerizable monomer or monomers arecopolymerized in the presence of the live preformed binary copolymer.The products formed by this method have a number of advantages, forexample, they are more homogeneous and have certain improved propertiessuch as better solubility over the products obtained from analogousbatch processes. The continuous polymerizations contemplated herein fallinto two main groups: (1) those 'which are used in equipment whichpermits the continuous addition of reactants and the continuous removalof product (continuous process) and (2) those which are used in batchreactions wherein one or more of the re actants is added continuouslyduring-the course of the polymerization, but from which no material isremoved during the reaction (continuous batch process). In the preferredprocess, acrylonitrile and the other monomer or monomers containing thespecified amount of a regu- I lator such as tertiary dodecyl mercaptanis placed in a suitable storage or supply vessel under an atmosphere ofnitrogen. In another storage vessel there is placed under nitrogen,air-free deionized water containing the appropriate amounts of otherreactants such as the live preformed copolymer modifier contained in itspolymerization reaction mixture which may contain some unreactedmonomer, an appropriate amount of additional catalyst and an acidicreagent such as phosphoric acid for adjusting the pH of the reactionmixture. A third vessel contains an activator such as potassiummetabisulfite in solution in air-free deionized water.

The preferred procedure is to draw continuously the appropriate amountsof solutions or dispersions from the supply vessels to the reactor,subject the mixture to polymerizing conditions, and continuously removefrom the reactor the modified polymer containing from 5 to 95% by weightof combined acrylonitrile. By this means from 70% to substantially 100%of the monomer can be converted to modified polymer. The length of timebetween the addition of ingredients to the reactor and the removal ofpolymer is defined as the contact time. At equilibrium, the polymeremulsion or slurry is removed from the reactor by suitable means at thesame total rate as ingredients from the storage vessels are being added.Thus, the contact time in the reactor can be conveniently controlled bythe absolute rate of addition of the reactants. Usually, the contacttime is between 1 and 3 hours, although longer periods in some cases areadvantageous. It will be understood, however, that the above process canbe varied in a number of ways. For example, the ingredients to be addedcan be combined or separated by 'using a larger number of vessels, or asa practical minimum-two storage vessels, one for the activator and onefor theother ingredients. Also the other monomer can be added to thereactor separately or in combination with the acrylonitrile or incombination with one or more of the other ingredients.

In the other continuous process, i. e. the continuous batch process, thevarious ingredients can also be added to the reactor in a number ofways, for example, as follows: (a) the catalyst, activator, acidcomponent, copolymer modifier, water, etc. are placed in the reactionvessel, and the monomers and regulator are added continuously; (b) themonomers, regulator, catalyst, acid component, copolymer modifier,water, etc., are placed in the reaction vessel and the activator isadded continuously; (c) the monomers, regulator, activator, acidcomponent, copolymer modifier, water, etc., are placed in the reactionvessel and the catalyst is added continuously; (d) the monomers,regulator, acid component, copolymer modifier, water, etc., are placedin the reaction vessel and both catalyst and activator, combined orseparate, are added continuously; (e) the copolymer moditier, catalyst,acid component and water are placed in the reaction vessel, and themonomers and activator, com bined or separate, are added continuously;(f) processes similar to (a) through (e), except that the acid componentis eliminated; and (g) processes similar to (a) through (f), except thatthe activator is eliminated. For further details of the continuousprocess, reference can be had to copending application of Coover andShields, Serial No. 407,954, filed of even date herewith.

The following examples will serve to illustrate further the mannerwhereby I practice my invention.

Example 1 2.5 g. of fumaramide, 0.5 g. of acrylonitrile were emulsifiedin cc. of distilled water containing 0.05 g. of ammonium persulfate,0.05 g. of sodium bisulfite, and 1 g. of a sulfonated ether (Triton720). The resulting emulsion was then heated at 35 C. for 12 hours. wasthen added 6.9 g. of acrylonitrile, 0.1 g. of fumaramide, 0.1 g. ofammonium persulfate and 0.1 g. of sodium bisulfite and thepolymerization mixture was heated at 35 C. for an additional 12 hours.The precipitated polymer was obtained in an percent yield and contained69 percent by weight of acrylonitrile based on analysis. Fibers spun byextruding the solution of the polymer product in N,N-dimethylformamideinto a precipitating bath had a softening temperature of 215 C., anextensibility of 26 percent and showed excellent afiinity for dyes.Fibers obtained from the solution of the mechanical mixture of 5 partspolyacrylonitrile and parts of the above polymer and extruding thesolution into a precipitating bath, had a tenacity of 3.2 g. per denier,an extensibility of 24 percent and a sticking temperature of 215 C.

Example 2 6.8 g. of acrylonitrile, 0.2 g. of N,N-dimethylfumaramide wereemulsified in cc. of distilled water having dissolved therein 0.1 g.potassium persulfate, 0.1 g. of sodium bisulfite, 1 g. oforthophosphoric acid, and 2 g. of aryloxypolyalkylene sulfonated ether(Triton 720). The emulsion was then heated at 35 C. for 8 hours. Therewas then added 1 g. of acrylonitrile and 2 g. of N,N-dimethvlfumaramideand heating was resumed for an additional 12 hours at 50 C. Theprecipitated polymer was obtained in a 93 percent yield and contained 68percent by weight of acrylonitrile on analysis. Fibers spun by extrudingthe solution of the polymer product in N,N-dimethylformamide into aprecipitating bath, had a softening point of 220 C., an extensibility of24 percent, and showed excellent dye susceptibility.

Example 3 1 g. of N,N,N',N'-tetramethylfumaramide and l g. ofN,N-dimethylacrylamide were emulsified in 50 cc. of water containing0.05 g. (calculated as 100 percent) of There lution was cooled to roomte'mp er'at'ure.

. 9 hydrogen peroxide 0.5 g. of oxalic acid and 2 g.- of.aryloxylpolyalkylene sulfonated ether (Triton 720) and the solution washeated at 50 C. for 12 hours. The solution was cooled to roomtemperature and 7.5 g. of acrylonitrile, 0.5 g. ofN,N-dimethylacrylamide, and 0.1 g. (calculated as 100 percent) ofhydrogen peroxide were added. Heating was then continued for anadditional 16 hours at 50 C. The precipitated polymer was obtained in a95 percent yield and contained 8 percent by weight ofN,N,N',N-tetramethylfumaramide and 9.3 percent by weight ofN,N-dimethylacrylamide. Fibers spun by extruding the solution of thepolymer product in N,N-dimethylformamide into a precipitating bath, hada softening point of 210 C.,- an extensibility of 26 percent and showedexcellent afiinity for dyes. The polymers can be mixed withpolyacrylonitrile or copolyrners of acrylonitrile containing 85 percentor more of acrylonitrile in all proportions and dissolved to give stablesolutions which do not separate into distinct layers on standing, andfrom which fibers and films of homogeneous character can be spun,extruded or cast.

Example 4 1 g.'ot N,N-di-isopropylfumaramide and 1.5 g. ofN,N-diethylmaleamide were emulsified in 100cc. of distilled Water havingdissolved therein 0.05 g. of ammonium persulfate, 0.05 g. of sodiumbisulfite, and 3 g. of potassium laurate. The solution was then heatedat 40 C. for 12 hours, at the end of which time the so- There was thenadded 7.1 g. of acrylonitrile, .4 "g. "of N,N"-di-isopropylfumaramide,0.1 g. of ammonium persulfate, and 0.1 g. of sodium bisulfite and thereaction mixture was heated an additional 12 hours at 35 C. Theprecipitated polymerwas obtained in a 94 percent yield and containedapproximately 71 percent acrylonitrile on analysis.

parts polyacrylonitrile and 5 parts'of the above polymer and extrudingthe solution into a precipitatingbath, had a tenacity of 3.5 g. perdenier, an extensibility of 24 percent and a sticking temperature of 225C.

Example 5 1 g. of methylmcthacrylate and 2 g. of N,N-dimethylmaleamidewere dissolved in 50 cc. of acetonitrile containing 0.5 g. of benzoylperoxide and the solution was heated at 50 C. for 24'hours. The solutionwas cooled to room temperature and 6.5 g. of acrylonitrile, 0.5 g. of'methylmethacrylate, and 0.1 g. of benzoyl peroxide were added. Thereaction mixture was then heated at 50 C. for an additional 16 hours.The precipitated polymer was obtained in a 96 percent yield andcontained approximately 65 percent acrylonitrile on ana1ysis. Fibersspun by extruding the solutionof the polymer product obtained above inN,N-dimethylacetamide "into a precipitating bath had a softening pointof 215 C., an extensibility of 27 percent and showed excellent .affinityfor dyes.

Example 6 I 1 g. of vinyl acetate and 1 g. of N-methylfumaramide weresuspended in 18 cc. of distilled water contaimng 0.02 g. of ammoniumpersulfate, 0.02-g. oflsodium b1- sulfite, and 1.1 g. of 'Triton 720.'(a 'sulfonatedether). The resulting emulsion was then heated at50' C.for 16 1 heated at 35 C. for 8 hours.

hours. After cooling to room temperature a dispersion of 7.1 g. ofacrylonitrile, 0.9 g. of vinyl acetate, and 0.1 g. of ammoniumpersulfate and 0.1 g. of sodium bisulfite and 1 g. of Triton 720 (asulfonated ether) in 50 cc. of distilled water was added. The reactionmixture was then tumbled at 50 C. for 12 hours, The precipitated polymer weighed 9.7 g. and contained 9 percent by weight of N-methylfumaramide on analysis. Fibers spun by extruding the solution of thepolymer product in N,N-dimethylformamide into a precipitating bath, hada softening point of 215 C. and showed good dye affinity. The polymerscan be mixed with polyacrylonitrile or copolymers of acrylonitrilecontaining percent or more acrylonitrile in all proportions anddissolved to give clear, stable solutions which do not separate intodistinct layers when standing, and from which fibers and films ofhomogeneous character can be spun, extruded or cast. Fibers obtainedfrom the solution of the mechanical mixture of 50 partspolyacrylonitrile and 50 parts of the above polymer and extruding thesolution into a precipitating bath had a tenacity of 3.4 g. per denier,an extensibility of 26 percent and a sticking temperature of 210 C.

Example 7 1.3 g. of N,N-dimethylethylfumaramate and 1 g. of methylfumaramate were suspended in'20 cc. of distilled water containing 0.02g. of ammonium persulfate, 0.02 g. of .sodium bisulfite and 1 g. ofTriton 720 (a sulfonated ether). The resulting emulsion was then heatedat 50 C. for 16 hours. After coolingto room temperature, a dispersion'of 7 g. of acrylonitrile, .7 g. of N,N-di'methylethylfumaramate, 0.1 g.of ammonium persulfate, 0.1 g. of sodium bisulfite and 1 g. of Triton720 (asulfonated ether) in 50 cc. of water was added. The dispersion wastumbled end over end .at 50 C. for an additional 12 hours.'lheprecipitated polymer weighed 9.4 g; and contained 29'percent byweight of thefumaramates by analysis. Fibers spun by extruding asolution of the polymer product in 'y-butyrlactone into a precipitatingbath, had a softening point of 220 C., an extensibility of 34 percentand showed good dye affinity.

The polymers can be mixed with polyacrylonitrile in all proportions anddissolved to give stable solutions which do not separate into distinctlayers on standing and from which fibers and films of homogeneouscharacter can be spun, extruded or cast.

. Example 8 2.4 g. of methyl-u-acetarninoacrylate and 2 g. of N- methylmethylrnaleamate were added to a solution of 0.05 g. of ammoniumpersulfate, 0.05 g. of sodium 'bisulfite and 2 g. of Triton 720 (asul'fonated ether) in 75 cc. of distilled water. The reaction mixturewas then After cooling to room temperature, 5 g. of acrylonitrile, .6 g.o'f'methyl-a-acetaminoacrylate, 0.05 g. of ammonium persulfate and 0.05g. of sodium bisulfite were added and heating was continued for 8 hoursat'35 C. The resulting polymer was obtained in a percent yield andcontained 29 percent by weight of methyl-u-acetaminoacrylate byanalysis. Fibers spun by extruding a solution of this'polymer product inN,N-di'm-ethylformamide into a precipitating bath, had a softening pointof 235 C., an extensibility of 36 percent and showed excellent afiinityfor dyes.

Example 9 1 g. of acrylonitrile and 3 g. of N-methyl methylitaconamatewere emulsified in 5 0 cc. of distilled water containing 0.04 g. ofpotassium persulfate and 0.04 g. of ammoniurn bisulfite and 1 g. ofpotassiumlaurate. The resulting emulsion was'heated for 16hours at 25 C.and cooled to roomtemperature, then 5.1 g.-of acrylonitrile and'0L9-g;of vinyl acetate were added along with 70.06 5g. potassium persulfate.The reaction mixture was al- .lowed to stand for 48 hours at roomtemperature. The

precipitated product was then filtered, washed several times with freshsources of distilled water and dried. There was thus obtained 9.5 g. ofpolymer containing 29 percent by weight of N-methyl methylitaconamate.Fibers prepared from this polymer had a softening point of 205 C., anextensibility of 37 percent and showed good dye affinity.

Example 4.9 g. of N-isopropylmethacrylamide, 1 g. of N,N-dimethylmethylitaconamate were dissolved in 50 cc. of acetonitrile containing0.1 g. of benzoyl peroxide. The resulting solution was heated for 16hours at 50 C. and cooled to room temperature. There was then added 4 g.of acrylonitrile, 0.1 g. of N-isopropylmethacrylamide and 0.1 g. ofbenzoyl peroxide and the reaction mixture heated for an additional 12hours at 50 C. The product was filtered off, washed with distilled waterand dried. The dried product contained approximately 40.0 percent byweight of acrylonitrile and a stable homogeneous solution resulted whenthe product was dissolved in N,N-dimethylacetamide containingpolyacrylonitrile.

Example 1 3 g. of N-isopropylethylitaconamate and 4.3 g. of methyleitr'aconamate were emulsified in 75 cc. of distilled water containing0.1 g. of ammonium per-sulfate and 0.1 g. of sodium bisulfite and 4 g.of Triton 720 (a sulfonated ether). The resulting emulsion was heated at50 C. for 16 hours. After cooling to room temperature, 2 g. ofacrylonitrile, 0.2 g. of methylcitraconamate, 0.1 g. of ammoniumpersulfate and 0.01 g. of sodium bisulfite were addded. The reactionmixture was then tumbled end over end for 12 hours at 50 C. The productwas filtered off, Washed with water and dried. It contained percent byweight of acrylonitrile on analysis and formed homogeneous solutions inN,N-dimethylformamide with polyacrylonitrile.

Example 12' 6.8 g. of N-methylisopropylcitraconamate and 2 g. ofacrylonitrile were suspended in 150 cc. of distilled water containing1.5 cc. of 7-ethy1-2-methylundecane-4-sulfonic acid sodium salt(Tergitol No. 4), 0.1 g. of ammonium persulfate and 0.1 g. of sodiumbisulfite. After tumbling the reaction mixture in a crown-capped bottlefor 20 hours in a water bath heated at 35 C., the resulting emulsion wasdiluted to 230 cc. with distilled water and 23 g. of acrylonitrile, 1.2g. of N-methylisopropylcitraconamate were added along with 1.5 cc. of7-ethyl-2-methylundecane-4-sulfonic acid sodium salt (Tergitol No. 4),0.23 g. of ammonium persulfate, 0.23 g. of sodium metabisulfite and 1.35g. of 85 percent phosphoric acid. The reac- 2 g. of N-methylmethacrylamide and 0.02 g. of acrylonitrile were dissolved in 75 cc. ofwater (distilled) containing 0.05 g. of ammonium persulfate and 0.05 g.of sodium bisulfite. The polymerization mixture was then heated at 35 C.for 12 hours. There were then added 7.48 g. of acrylonitrile, 0.5 g. ofN-methyl methacryl-' amide, 0.1 g. of ammonium persulfate and 0.1 g. ofsodium bisulfite and the polymerization mixture was heated at 35 C. foran additional 12 hours. The precipitated productwas obtained in a 90percent yield and contained "24 percent by weight of N-methylmethacrylamide.

-12 Fibers spun by. extruding a solution of the polymer product inN,N-dimethylformamide into a precipitating bath, had a softening pointof 210 C., an extensibility of 28 percent and showed excellent afiinityfor dyes. Fibers obtained by preparing a solution from the merchanicalmixture of 5 parts of the above polymer and 95 parts ofpolyacrylonitrile and extruding the solution into a precipitating bath,had a tenacity of 3.4 g. per denier, an extensibility of 22 percent, asticking temperature of 210 C. and shrank only 6 percent in boilingwater.

Example 14 l g. of acrylonitrile and 2 g. of Nmethylacrylamide wereadded to 100 cc. of distilled water, having dissolved therein 0.05 g. ofpotassium persulfate and l g. of ortho phosphoric acid. The solution wasthen heated at 50 C. for 12 hours. There were added 6.9 g. ofacrylonitrile, 0.1 g. of dimethylfumarate. 0.1 g. of potassiumpersulfate, 0.1 g. of sodium bisulfite to the cooled reaction mixtureand heating was resumed for 8 hours at 35 C. The precipitated polymerwas obtained in a percent yield and contained 18 percent by weight ofN-methyl acrylamide. Fibers spun by extruding a solution of the polymerin N,N-dimethylformamide into a precipitating bath, had a softeningpoint of 220 C. and showed excellent dye susceptibility. Fibers obtainedby preparing a solution from a mechanical mixture of partspolyacrylonitrileand 5 parts of the above polymer and extruding thesolution into a precipitating bath, had a tenacity of 3.4 g. per denier,an extensibility of 20 percent, a sticking temperature of 210 C. andshrank only 5 percent in boiling water.

Example 15 l g. of methacrylamide and l g. of N,N-dimethylacrylamidewere added to 50 cc. of water containing 0.05- g. (calculated aspercent) hydrogen peroxide and 0.5 g. of oxalic acid and the solutionwas heated at 50 C. for 12 hours. The solution was cooled to roomtemperature and 7.7 g. of acrylonitrile, .3 g. of methacrylamide and 0.1g. (calculated as 100 percent) of hydrogen peroxide were added. Heatingwas then continued for an additional 16 hoursat 50 C. The precipitatedpolymer was obtained in a 92 percent yield and contained 9 percent byweight of N,N-dimethylacrylamide. Fibers spun by extruding a solution ofthe polymer product in N,N-dimethylformamide into a precipitating bath,had a softening point of 195 C., an extensibility of 26 percent andshowed excellent atfinity for dyes.

Example 16 2.47 g. of N,N-dimethylitaconamide and 0.03 g. of acrylamidewere added to 100 cc. of distilled water having dissolved therein 0.05g. of ammonium persulfate and 0.05 g. of sodium bisulfite. The solutionwas then heated at 40 C. for 12 hours, at the end of which time thesolution was cooled to room temperature. There were then added 7 g. ofacrylonitrile, 0.5 g. of styrene, 0.1 g. of ammonium persulfate and 0.1g. of sodium bisulfite and the reaction mixture was heated for anadditional 12 hours at 35 C. Theprecipitated polymer was obtained in a92 percent yield and contained approximately 24 percent by weight ofN,N-dimethylitaconamide. Fibers spun by extruding a solution of thepolymer product in N,N-dimethylformamide into a precipitating bath had asoftening point of 220 C. and showed good afiinity for dyes. Fibersobtained by preparing a solution from a mechanical mixture of 50 partsof the above polymer and 50 parts of an acrylonitrile polymer containing90 percent acrylonitrile and 10 percent vinyl acetate and extruding thesolution into a precipitating bath, had a tenacity of 3.2 g. per denier,an extensibility of 28 percent, a sticking temperature of C., and shrankonly 12 percent in boiling water.

13 Example 17 1 g. of methyl methacrylate and 2 g. of N-methylacrylamidewere dissolved in 50 cc. of acetonitrile containing 0.05 g. of benzoylperoxide and the solution was heated at 50 C. for 24 hours. The solutionwas cooled to room temperature and 6.8 g. of acrylonitrile, .2 g. ofisopropenyl acetate and 0.1 g. of benzoyl peroxide were added. Thereaction mixture was then heated at 50 C. for an additional 16 hours.The precipitated polymer was obtained in a 95 percent yield andcontained 19.5 percent by weight of N-methylacrylamide on analysis.Fibers spun by extruding a solution of the polymer product obtainedabove in N,N-dimethylacetamide into a precipitating bath, had asoftening point of 205 C., an extensibility of 28 percent and showedexcellent afiinity for dyes. Fibers obtained by preparing a solutionfrom a mechanical mixture of 95 parts of the above polymer and 5 partsof an acrylonitrilepolymer containing 95 percent of acrylonitrile and 5percent isopropenyl acetate and extruding the solution into aprecipitating bath, had a tenacity of 3.1 g. per denier, anextensibility of 25 percent, a sticking temperature of 195 C. and shrankonly 12 percent in boiling water.

Example 18 7.5 g. of acrylonitrile and 0.5 g. of methyl methacrylatewere emulsified in 80 cc. of water containing 2 g. of Triton 720 (a.sulfonated ether), 0.1 g. of ammonium persulfate and 0.1 g. of sodiumbisulfite. The resulting emulsion was then heated at 50 C. for 16 hoursand after cooling to room temperature, a dispersion of l g. of vinylacetate, 1 g. of methyl 'methacrylate suspended in 18 cc. of distilledwater containing 0.02 g. of ammonium persulfate and 0.02 g. of sodiumbisulfite and l g. of Triton 720 (a sulfonated ether) was added. Thereaction mixture was then tumbled at 50 C. for an additional 6 hours.The precipitated polymer weighed 9.7 g. and contained percent by weightof vinyl acetate on analysis. Fibers spun by extruding a solution of thepolymer product in N,N-dimethylformamide into a precipitating bath, hada softening point of 200 C., an extensibility of 26 percent and showedgood dye aflinity.

Example 19 6.8 g. of acrylonitrile and 0.2 g. of N-methylacrylamide wereemulsified in 75 cc. of water containing 2 g. of Triton 720 (asulfonated ether), 0.1 g. of ammonium persulate, 0.1 g. of sodiumbisulfite. The resulting emulsion was then heated at 35 C. for 6 hours.After cooling to room temperature, a dispersion of 2 g. of vinyl acetateand 1 g. of isopropenyl acetate in 20 cc. of distilled water containing0.02 g. of ammonium persulfate, 0.02 g. of sodium bisulfite and 1.1 g.of Triton 720 (a sulfonated ether) was added. The dispersion was tumbledend over end at 50 C. for an additional 12 hours. The precipitatedpolymer weighed 9.7 g. and contained 29 percent by weight of isopropenyland vinyl acetate on analysis. Fibers spun from a solution of thepolymer product in N,N-dimethyltormamide into a precipitating bath, hada softening point of 195 C., an extensibility of 26 percent and showedgood dye affinity. The polymers can be mixed with polyacrylonitrile inall proportions and dissolved to give stable solutions which do notseparate into distinct layers on standing and from which fibers andfilms of homogeneous character can be spun, extruded or cast.

Example 20 2.5 g. of methyl-a-aminoacrylate and 2 g. of acrylonitrilewere added to a solution of 0.05 g. of ammonium persulfate and 0.05 g.of sodium bisulfite in 75 cc. of distilled water. The reaction mixturewas then heated to 35 C. for 8 hours. After cooling to room temperature,5 g. of acrylonitrile, 0.5 g. of methyl-a-aminoacrylate, 0.05 g. ofammonium persulfate and 0.05 gram of sodium 14 bisulfite were added andheated for an additional 8 houfs at 35 C. The resulting polymercontained a 93 percent yield and contained 29 percent by weight ofmethyl-aaminoacrylate. Fibers spun by extruding a solution of thispolymer product in N,N-dimethylformamide into a precipitating bath, hada softening point of 235 C., an

ext'ensibility of 27 percent and showed excellent afiinity for dyes.

Example 21 1 g. of acrylonitrile and 2.5 g. of N-methyl methacrylamidewere dissolved in 50 cc; of distilled water containing 0.04 g. ofpotassium bisulfite and 0.04 g. of ainmonium persulate. The resultingsolution was heated for 16 hours at 25 C. and cooled to roomtemperature.- Then 6 g. of acrylonitrile, 0.5 g. of N-methylmethacrylamide were added along with 0.06 g. of potassium bisulfite. Thereaction mixture was allowed to stand for 48 hours at room temperature.The precipitated product was then filtered ofi, washed several timeswith fresh portions of distilled water and dried. There were thus.obtained 9.2 g. of a polymer containing 26 percent by weight ofN-methyl methacrylamide. Fibers prepared from this polymer had asoftening point of 210 C., an extensibility of 25 percent'and showedgood affinity for dyes.

methacryla'mide were dissolved in 50 cc. ofdistill'ed water containing0.3 g. of potassium bisulfite and 0.03 g. of potassium persulfate. Theresulting solution was heated for 16 hours at 30 C. 8 g. ofacrylonitrile and 0.5 g. of N-isop'ropylacrylamide were added along with0.06 g. of potassium bisulfite and 0.06 g. of potassium persulfate. Thereaction mixture was allowed to stand for 48 hours at room temperature.The precipitated product was then filtered off, washed several timeswith fresh portions of distilled water and dried. The resulting polymerwas easily soluble in such solvents as N,N- dimethylacetamide, N,Ndimethylformamide and 7- butyrolactone etc., to give clear, high solids,gel-free solutions. Fibers prepared from thispolymer had a highsoftening point and showed excellent aflinity for dyes.

Example 23 2 g. of acrylonitrile and 0.2 g. of vinyl acetate wereemulsified in cc. of water containing 0.01 g. of ammonium persulfate,0.01 g. of sodium bisulfite and 3 g. of Triton 720 (a sulfonated ether).The resulting emulsion was heated at 35 C. for 6 hours. After cooling toroom temperature, 5 g. of vinyl acetate and 4.8 g. of methyl acrylatewere suspended in 20 cc. of distilled water containing 0.1 g. ofammonium persulfate and 0.1 g. of sodium bisulfite and 3 g. of Triton720 (a sulfonated ether) were added. The reaction mixture was thentumbled end over end for 12 hours at 50 C. The product was filtered olf,washed with water and dried. It contained 18.5 percent by weight ofacrylonitrile by analysis and formed homogeneous solutions inN,N-dimethylformamide with polyacrylonitrile.

Example 24 2 g. of itaconamide and 0.5 g. of N-methylacrylamide wereemulsified in 80 cc. of water containing 0.05 g. of ammonium'persulfate, 0.05 g. of sodium bisulfite and 3 g. of Triton 720 (asulfonated ether). The resulting emulsion was heated at 35 C. for 12hours. 7 g. of acrylonitrile and 0.5 of isopropenyl acetate along with0.1 g. of ammonium persulfate and 0.1 g. of sodium bisulfite were addedto the cooled emulsion. The polymerization was completed by heating at35 C. for an additional 5 hours. a 94 percent yield and contained 69.8percent acrylonitrile by weight based on analysis.

The resulting polymer was obtained in by filtration yielding 7.3 g. ofpolymer.

Example 25 2.5 g. of citraconamide and 0.5 g. of dimethylfumarate wereemulsified in 90 cc. of water containing 0.05 g. of ammonium persulfate,0.02 g. of sodium bisulfite and 2.5 g. of Triton 720 (a sulfonatedether). The resulting emulsion was heated at 35 C. for '5 hours. 6.8 g.of acrylonitrile and 0.2 g. of dimethylmaleate along with 0.1 g. ofammonium persulfate, 0.1 g. of sodium bisulfite and l g. of Triton 720(a sulfonated ether) were then .added. The polymerization was completedby heating at 40 C. for 4 hours. The resulting polymer was obtained in a92 percent yield and contained 67.9 percent by weight acrylonitrilebased on analysis. Fibers obtained from the polymer had a softeningtemperature of 210 C. and an extensibility of 29 percent.

Example 26 3.0 g. of acrylonitrile and 7.0 g. of N-methyl methacrylamidewere emulsified in 40 cc. of water containing 0.15 g. of potassiumpersulfate and 0.01 g. of tertiary dodecyl mercaptan. The emulsion washeated at 60 C. until 94% or more of the monomers had copolymerized.This result is usually accomplished by heating for about 12 hours. Thecopolymer contained approximately 30% by weight of acrylonitrile and 70%by weight of N-methyl methacrylamide. The mixture was then cooled toroom temperature, 50 cc. of water added and the mixture agitated until ahomogeneous solution or dope containing by weight of the copolymerresulted.

30.7 g. (3.07 g. of copolymer) of the above prepared solution or dope ofthe copolymer were placed in a jacketed reactor provided with anagitator and heat exchanger. There were then added 10 g. ofacrylonitrile, 114 cc. of water, 0.58 g. of 85% phosphoric acid, 0.1 g.of potassium persulfate, 0.17 g. of potassium metabisulfite, 0.1 g. oftertiary dodecyl mercaptan and 0.56 g. of a 30% solution in water ofN-methyl methacrylamide and the mixture heated, with stirring, to 35 C.and then allowed to level off at 3739 C. After the heat ofpolymerization had been removed and when the conver sion of theacrylonitrile to polymer had reached 96% or more, which is usuallyaccomplished in a period of about 12 hours, the temperature was raisedto 90 C. The mother liquor was removed by centrifuging thepolymerization mixture, the polymer precipitate being reslurried twicewith water and centrifuged to a 70% moisture cake. The cake was driedunder vacuum at 80 C. in an agitated dryer. The overall yield ofmodified polyacrylonitrile productwas over 90%. After hammermilling, thedry powder, now ready for spinning, was

stored in a moisture proof container. A generally similar product canalso be obtained by either of the continuous processes previouslydescribed.

The modified polyacrylonitrile prepared as above and containing about18% by weight of N-methyl methacrylamide was soluble inN,N-dimethylformamide. Fibers spun by extruding a solution of thepolymer product in 'N,N-dimethylformamide into a precipitating bath hada softening temperature of about 240 C., an extensibility of about 20-30percent depending on the drafting and relaxing conditions, and showedexcellent affinity for dyes.

Example 27 One and four-tenths g. of N-methyl methacrylamide and 0.6 g.of acrylonitrile were dissolved in 8 cc. of water along with 0.03 g. ofpotassium persulfate. The solution was allowed to polymerize at 60 C. to70 conversion. There was then added 100 g. of water, 8 g. ofacrylonitrile, 0.1 g. of potassium persulfate and 0.1 g. of potassiummelabisulfite and the mixture was allowed to polymerize at 35 C. to a75% conversion. The polymer product was then separated immediately fromthe reaction mixture The polymer was readily soluble in such solvents asN,N-dimethylformamide, N,N-dimethylacetamide and 'y-butyrolactone togive clear, gel-free solutions. Fibers obtained by extruding a solutionof the polymer into a precipitating bath had good physical properties.

Example 28 One and four-tenths g. of N-methyl methacrylamide and 0.6 g.of acrylonitrile were dissolved in 8 cc. of water along with 0.03 g. ofpotassium persulfate. The solution was allowed to polymerize at 60 C. to85% conversion. There was then added 100 g. of water, 8 g. ofacrylonitrile, 0.1 g. of potassium persulfate and 0.1 g. of potassiummetabisulfite and the mixture was allowed to polymerize at 35 C. to an85% conversion. The polymer product was then immediately separated fromthe reaction mixture by filtration yielding 8.4 g. of polymer. Thepolymer was readily soluble in such solvents as N,N-dimethylformamide,N,N-dimethylacetamide and 'y-butyrolactone to give clear, gel-freesolutions. Fibers obtained by extruding a solution of the polymer into aprecipitating bath had good physical properties.

Properties 29 Four and nine-tenths g. of N-isopropyl methacrylamide, 1g. of N,N-dimethyl methyl itaconamate were dissolved in 50 cc. ofacetonitrile containing 0.1 g. of benzoyl peroxide. The resultingsolution was heated for 16 hours at 50 C. at the end of which time thepolymerization was substantially complete. The reaction mixture wascooled and 4 g. of acrylonitrile, 0.1 g. of N-isopropyl methacrylamide,0.1 g. of methyl acrylate and 0.1 g. of benzoyl peroxidewere then added.The reaction mixture was heated at 50 C. until the polymerization hadproceeded to conversion. The product was then filtered off, washed withdistilled water and dried. The dried product was readily soluble in suchsolvents as LN-dimethylacetamide and N,N-dimethylformamide and stablehomogeneous solutions resulted when the product was dissolved inN,N-dimethylacetamide containing polyacrylonitrile.

Example 30 Two g. of N-methyl methacrylamide and 0.2 g. of N tertiarybutyl acrylamide were dissolved in cc. of water containing 0.05 g. ofammonium persulfate and 0.05 g. of sodium bisulfite. The polymerizationmixture was heated at 35 C. until a 70% conversion was obtained. Therewas then added 7.4 g. of acrylonitrile, 0.5 g. of N- methylmethacrylamide, 0.1 g. of ammonium persulfate and 0.1 g. of sodiumbisulfite and the polymerization mixture was heated at 35 C. for anadditional 12 hours.

At the end of this time the polymerization was essentially complete. Theprecipitated product was obtained in a 90% yield and was readily solublein such solvents as N,N dimethylacetamide and N,N dimethylformamide.Fibers spun by extruding a solution of the polymer product inN,N-dimethylformamide into a precipitating bath had a softening point of210 C., an extensibility of 28% and showed excellent aflinity for dyes.

Example 31 One g. of N-isopropyl acrylamide and 0.5 g. of N-methylacrylamide were dissolved in 50 cc. of distilled water containing 0.3 g.of potassium bisulfite and 0.03 g.

of potassium persulfate. The solution was allowed to polymerize at roomtemperature to an conversion. Eight g. of acrylonitrile and 0.5 g. ofmethyl acrylate were immediately added along with 0.06 g. of potassiumbisulfite and 0.06 g. of potassium persulfate. The reaction mixture wasallowed to polymerize at room temperature to a conversion. Theprecipitated product was then filtered off, washed several times withfresh portions of distilled water and dried. The resulting polymer waseasily soluble in such solvents as N,N-dimethylacetamide,N,N-dimethylformamide and 'y-butyrolactone to give clear, high solids,gel-free solutions. Fibers '17 prepared from this polymer had a highsoftening point and showed excellent affinity for dyes.

Exampi: 32

Two and five-tenths g. of fumaramide, 0.5 g. of acrylonitrile wereemulsified in 75 cc. of distilled water containing 0.05 g. of ammoniumpersulfate, 0.05 g. of sodium bisulfite and 1 g. of a sulfonated ether(Triton 720). The resulting emulsion was then heated or allowed topolymerize at 35 C. to an 85% conversion. There was then added 6.9 g. ofacrylonitrile, 0.1 g. of fumaramide, 0.1 g. of ammonium persulfate and0.1 g. of sodium bisulfite and the polymerization mixture was heated at35 for an additional 12 hours. At the end of this time thepolymerization had proceeded essentially to completion. The precipitatedpolymer was obtained in a 95% yield and contained approximately 69% byweight acrylonitrile based on analysis. Fibers spun by extruding asolution of the polymer product in N,N-dimethylacetamide into aprecipitating bath at a softening temperature of 210 C., anextensibility of 28% and showed excellent afiinity for dyes.

Example 33 Six and eight-tenths g. of acrylonitrile, 0.2 g. ofN,N-dimethylfumaramide were emulsified in 100 cc. of distilled waterhaving dissolved therein 0.1 g. of potassium persulfate, 0.1 g. ofsodium bisulfite, 1 g. of orthophosphoric acid and 2 g. of aryloxypolyalkalene sulfonated ether (Triton 720). The emulsion was then heatedat 35 C. for 8 hours at the end of which time the polymerization hadproceeded essentially to completion. There was then added 1 g. ofacrylonitrile and 2 g. of N,N'-dimethylfumaramide. The mixture wasallowed to polymerize at 50 C. to an 85% conversion. The precipitatedpolymer was readily soluble in such solvents as N,N-dimethylacetamideand N,N-dimethylformamide.

Fibers spun by extruding the solution of the polymer product inN,N-dimethylformamide into a precipitating bath had a softening point of215 C., an extensibility of 26% and showed excellent dye susceptibility.

Example 34 One g. of N,N,NN-tetramethyl fumaramide and l g. ofN,N-dimethylacrylamide were emulsified in 50 cc. of water containing0.05 g. (calculated as 100%) of hydrogen peroxide, 0.5 g. of oxalic acidand 2 g. of aryloxy polyalkalene sulfonated ether (Triton 720) and thesolution was allowed to polymerize at 50 C. to a conversion of 70%. Thesolution was cooled to room temperature and 7.5 g. of acrylonitrile, 0.5g. of N,N-dimethylacrylamide and 0.1 g. (calculated as 100%) of hydrogenperoxide Were added. The solution was allowed to polymerize at 50 C. toa 70% conversion. The precipitated. polymer was readily soluble in suchsolvents as N,N-dimethylformamide and N,N-dimethylacetamide. Fibers spunby extruding a solution of the polymer product in N,N-dimethylformamideinto a precipitating bath had a softening point of 205 C., anextensibility of 29% and showed excellent aifinity for dyes. The polymercan be mixed with polyacrylonitrile or copolymers of acrylonitrilecontaining 85% or more acrylonitrile in all proportions and dissolved togive stable solutions which do not separate into distinct layers onstanding and from which fibers and film of homogeneous character can bespun, extruded or cast.

Example 35 of vinyl acetate and 0.1 g. of ammonium persulfate and 0.1 g.of sodium bisulfite and 1 g. of Triton 720 (a sulfonated ether) and 50'cc. 5f distilled water was added. The reaction mixture was allowed topolymerize at 50 C. to a conversion. The precipitated polymer wasreadily soluble in such solvents as N,N-dimethylacetamide and'y-butyrolactone. Fibers spun by extruding a solution of the polymerproduct in N,N-dimethylformamide into a precipitating bath had asoftening point of 210 C. and showed good dye affinity. The polymers canbe mixed with polyacrylonitrile or copolymers of acrylonitrilecontaining 85% or more acrylonitrile in all proportions and dissolved togive clear, stable solutions which do not separate into distinct layerswhen standing and from which fibers and films of homogeneous charactercan be spun, extruded or cast.

Example 36 1 Two g. of acrylonitrile and two-tenths g. of vinyl acetatewere emulsified in cc. of water containing 0.01 g. of ammoniumpersulfate and 0.01 g. of sodium bisulfite and 3 g. of Triton 720 (asulfonated ether). The resulting emulsion was allowed to polymerize at35 C. to a conversion of After cooling to room temperature, 5 g. ofvinyl acetate and 4.8 g. of methyl acrylate were suspended in 20 cc. ofdistilled water containing 0.1 g. of ammonium-persulfate and 0.1 g. ofsodium bisulfite and 3 g. of Triton 720 (a sulfonated ether) were added.The mixture was allowed to polymerize at 50 C. to an 85% conversion. Theproduct was filtered ofi, washed with water 'and dried. The product wasreadily soluble in such solvents as N,N-dimethylformamide andN,N-dimethylacetamide. Fibers obtained by spinning a solution of thispolymer in such solvents as N,N-dimethylformamide into a precipitatingbath had excellent physical properties.

Example 37 2.5 g. of N-methylmethacrylamide and 0.5 g. acrylamide weredissolved in 75 ml. of water containing 0.05 g. of ammonium persulphateand 0.05 g. of sodium bisulfite. Polymerization was completed by heatingat 35 C. for 12 hours. 4.2 g. of vinyl chloride, 2 .8 'g. acrylonitrile,0.1 g. ammonium persulphate and 0.1 g.sodium-.bisulfite were then. addedand polymerization completed'by heating at 35 C. for an additional 12hours. Precipitated polymer was obtained in percent yield and contained21 percent amide by analysis. The resultant polymer is soluble inmethyl-ethylketone. Fibers obtained from the polymer have excellentaflinity for dyes.

Example 38 1 g. of N-isopropylacrylamide was added to ml. of watercontaining 0.05 g. of potassium persulphate and 0.05 g. of sodiumbisulfite and 1 g. of orthophosphoric acid. Polymerization was completedby heating at 35 C. for 12 hours. 6.4g. of acrylonitrile, 1.6 g. vinylchloride, 0.1 g. potassium persulphateand 0.1 g. sodium bisulfite wereadded to the cooled reaction mixture and the polymerization completed byheating at 35 C. for an additional 8 hours. The precipitated polymer wasobtained in a 90 percent yield and contained 18 percent amide byanalysis. The polymer is solvent in such solvents as cyclohexanone and'dimethylacetamide. The fibers obtained from this polymer show excellentafiinity for dyes.

I Example 39 4 g .of N,N-dimethylacrylamide were added to 100 ml. ofwater containing 0.01 g. of potassium persulphate and 0.01 g. of sodiumbisulfite. Polymerization was completed by heating at 35 C. for 12hours. 1.8 g. of acrylonitrile and 4.2 g. of vinyl chloride, 0.1 g.potassium persulphate and 0.1 g. of sodium bisulfite were added to thecooled reaction mixture and the polymerization was completed by heatingat 35 C. for an additional spans? 8 hours. The resultant polymer issoluble in such solvents as cyelohexanone, methylethylketone anddimethylformamide. Fibers obtained from this polymer show excellentafiinity for dyes.

The preceding description and examples have set forth that the resinouscompositions or polymers of the invention which contain from 60 to 95percent by weight of acrylonitrile in the polymer molecule areespecially useful for preparing fibers from their solutions or dopes inthe mentioned solvents by wet or dry spinning processes. Good qualityfibers can also be spun from dopes comprising a mixture of one or moreof the resinous compositions of the invention with polyacrylonitrile,when used in such proportions that the combined total of acrylonitrilein the mixture of components is in the range of 60 to 95 percent byweight. However, all of the resinous compositions or polymers of theinvention containing from to 95 percent of acrylonitrile, includingmixture of them with polyacrylonitrile in any proportions but preferablyin the proportions of from 5 to 95 parts by weight of one or more of thepolymers of the invention and 95 to 5 parts by weight ofpolyacrylonitrile, can be made up into solutions or dopes with one ormore acrylonitrile polymer solvents, with or without added fillers,pigments, dyes, plasticizers, etc., as desired, and the dopes coatedonto a smooth surface to give flexible and tough films and sheetmaterials, which are useful for photographic film support and otherpurposes.

Other solvents which can be used for the preparation of fibers andcoating compositions, etc. from the new resinous compositions orpolymers of the invention, and mixtures thereof with each other withpolyacrylonitrile or with acrylonitrile polymers containing 85 percentor more of acrylonitrile, include ethylene carbonate, ethylenecarbamate, *y-butyrolactone, N-methyl-Z-pyrrolidone, N,N-dimethylcyanamide, N,N-dimethyl cyanoacetamide,N,N-dimethyl-fl-cyanopropionamide, glycolonitrile (formaldehydecyanohydrin), malononitrile, ethylene, cyanohydrin, dimethyl sulfoxide,dimethyl sulfone, tetramethylene sulfone, tetramethylene sulfoxide,N-formyl pyrrolidine, N-formyl morpholine, N,N'-tetramethylenemethazephosphonamide, and the like. Generally speaking, I have foundthat N,N-dimethyl formamide and N,N-dimethyl acetamide are particularlyadvantageous solvents. The amount of my new resinous compositions in thesolvent can be varied from 25 to 40 percent or even higher in somecases, such solutions or dopes being especially well adapted topractical spinning operations.

In practicing this invention an especially valuable class of monomericmaterials containing a CH=C group are the vinylpyridines including boththe unsubstituted vinylpyridines such as 2-vinylpyridine and4-vinylpyridine as Well as the substituted vinylpyridines having one ormore alkyl groups of from one to four carbon atoms substituted on thering. Typical of the substituted vinylpyridines areZ-methyl-S-vinylpyridine and 2-vinyl-6- methylpyridine although any ofthe other substituted pyridines as described can be employed. Thevinylpyridine monomers are particularly useful when employed in formingthe initial copolymer which is thereafter reacted with a mixture ofacrylonitrile and another monomer. Thus, for example, these or similarvinylpyridines can be copolymerized with any of the 13 classes .ofmaterials which have been specifically described hereinabove. Aparticularly useful copolymer for forming the modifying base is thecopolymer of a. vinylpyridine with an acrylamide or methacrylamide.These copolymers when reacted with a mixture of acrylonitrile andanother monomer as described give modified polymers which have excellentdyeing characteristics and dyed fibers prepared therefrom show aparticularly high degree of light fastness, when dyed with acetate,wool, direct or vat dyes. Modified polymers of this kind are illustratedin .the following examples:

20 Example 40 4 g. of fumaramide and 6.0 g. of 2-methyl-5-vinylpyridinewere emulsified in ml. of distilled water containing 1.0 g. of sodiumlauryl sulfate, 0.02 g. of potassium persulfate, and 0.02 g. of sodiummetabisulfite. The resulting emulsion was heated at 25 C. for 15 hours.There was then added 260 cc. of distilled water, 29.0 g. ofacrylonitrile, 1.0 g. of Z-methyl-S-vinylpyridine, 0.3 g. of potassiumpersulfate, and 0.3 g. of potassium metabisulfite. The polymerizationmixture was heated at 35 C. for 15 hours. The resultant precipitatedpolymer was isolated by filtration. It was readily soluble indimethylformamide and could be spun into fibers having a tenacity of 2.4g./d.

Example 41 28.5 g. of acrylonitrile and 1.5 g. of itaconamide wereemulsified in 190 cc. of distilled water having dissolved therein 0.3 g.of potassium persulfate, 0.3 g. of potassium metabisulfite, 1.5 g. ofphosphoric acid, and 1.5 g. of sodium lauryl sulfate. The emulsion wasthen heated at 35 C. for 10 hours. There was then added 4 g. ofitaconamicle, 6 g. of 2-methyl-5-vinylpyridine, 0.02 g. of potassiumpersulfate, and 0.02 g. of potassium metabisulfite and heating wasresumed for an additional 12 hours at 35 C. The precipitated polymer wasisolated by filtration and was readily soluble in dimethylformamide. Itcould be spun into fibers which, when com pletely relaxed, had anextensibility of 27%.

Example 42 4 g. of citraconamide and 6.0 g. of 2-methyl-5-vinylpyridinewere emulsified in 190 ml. of water containing 1 g. of sodium laurylsulfate, 0.02 g. of potassium persulfate, and 0.02 g. of potassiummetabisulfite. The resulting emulsion was heated at 25 C. for 12 hours.There was then added 260 cc. of distilled water, 28.5 g. ofacrylonitrile, and 1.5 g. of citraconamide, 0.3 g. of potassiumpersulfate, and 0.3 g. of potassium metabisulfite. The polymerizationmixture was heated at 35 C. for 12 hours. The resultant polymer wasfiltered and dried and was soluble in dimethylformamide.

Example 43 1 g. of N-methylisopropylcitraconamate and 9.0 g. ofZ-methyl-S-vinylpyridine were added to a solution of 0.02 g. ofpotassium persulfate, 0.02 g. of potassium metabisulfite and 1.0 g. ofsodium lauryl sulfate in 190 ml. of water, and the reaction mixture washeated at 25 C. for 10 hours. To the resultant emulsion was added 260cc. of distilled water, 28.0 g. of acrylonitrile, 1.0 g. of 2-methyl-S-vinylpyridine, 1.0 g. of N-methylisopropylcitraconamate, 0.3 g.of potassium persulfate, and 0.4 g. of potassium metabisulfite. Thepolymerization mixture was heated at 35 C. for 15 hours. The product wascompletely soluble in dimethylformamide.

Example 44 5 g. of acrylonitrile and 5.0 g. of Z-methyl-S-vinylpyridinewere added to 190 cc. of water containing 1.0 g. of sodium laurylsulfate, 0.1 g. of potassium persulfate, and 0.1 g. of potassiummetabisulfite. The resulting emulsion was allowed to polymerize for 15hours at 35 C. There was then added 860 cc. of Water containing 103.0 g.of acrylonitrile, 2.0 g. of 2-methyl-5-vinylpyridine, 1.0 g. ofpotassium persulfate, and 1.0 g. of potassium metabisulfite. Thepolymerization mixture was heated at 35 C. for 15 hours. The resultantpolymeric product was completely soluble in dimethylformamide and couldbe spun into a fiber which had a tenacity of 3.2 g./d.

Example 45 2.7 g. of N-isopropylacrylamide, 0.3 g. of 2-methyl-5-vinylpyridine, and 0.3 g. of sodium lauryl sulfate were mixedlwell' in57 ml. of water, and. 0.03, g; of potassium persulfate and 0.03 g. ofpotassium metabisulfite were added. The resultant emulsic :1 was allowedto polymerize at 25 C. for 16 hours. There was then added 93 parts ofdistilled water containing 9.6 g. of acrylonitrile, 0.4 g. ofN-isopropylacrylamide, 0.15 g. of potassium persulfate and 0.150 g. ofpotassium. metabisulfite, and the mixture was allowed to polymerize at35 C. for 15 hours. The resultant polymer was soluble indimethylformamide and could be spun into fibers which had excellentalkali stability, and a-high atfinity for all classes of dyes. The dyedfiber had excellent resistance to fading.

Example 46 2.7 g. of N-methylmethacrylamide, 0.3 g. of Z-methyl-5-vinylpyridine, and 0.3 g. of sodium lauryl sulfate were mixed well in57 ml. of water, and 0.03 g. of potassium persulfate and 0.03 g. ofpotassium metabisulfite were added. The resulting emulsion was allowedto polymerize Example 47 2.94 g. of N,N-dimethylaorylamide and 0.06 g..of 4- vinylpyridine were suspended in 30 ml. of distilled watercontaining 0.15 g. of sodium lauryl sulfate, and 0.03 g. of potassiumpersulfate, and 0.03 g. of potassium metabisulfite were added. Theresulting emulsion was allowed to polymerize at 25 C. for 6 hours, atwhich time titration for residual N,N-dimethylacrylamide revealed that a70% conversion topolymer had occurred. There was then immediately added120 m1. of distilled water, 10 g. of acrylonitrile, 0.1 g. of potassiumpersulfate, and 0.1 g. of potassium metabisulfite. The polymerizationmixture was heated at 35 C. for 6 hours, at which time titration forunreacted acrylonitrile indicated that 70% of it had copolymerized withthe monomeric N,N-dimethylacrylamide. The polymer was immediatelycoagulated and isolated by filtration. It was completely soluble indimethylformamide.

All of the modified polymers prepared as described hereinabove showexcellent mechanical properties and improved affinity for dyes. Althoughthe invention has been described in considerable detail with particularreference to certain preferred embodiments thereof, it will beunderstood that variations and modifications can be effected within thespirit and scope of the invention as described hereinabove and asdefined in the appended claims.

WhatIclaim is:

1. A process for preparing a resinous fiber-forming graft copolymercontaining from 60 to 95% by weight of combined acrylonitrile whichcomprises contacting a polymerization reaction mixture consistingpredominantly of water and containing (1) a peroxide polymerizationcatalyst and (2) from 40 to 5 parts by weight of a copolymer consistingof from 50 to 99% by 'weight of an amide represented by the followinggeneral formula:

wherein R and R each represents a member selected from the groupconsisting of a hydrogen atom and an alkyl group of from 1 to 4 carbonatoms and R represents a member selected from the group consisting of .ahydrogen atom and a methyl group, and from 50 to 1% by weight of acompound, selected from the group consisting of a dissimilaramide'represented by the above general formula and acrylonitrile, thesaid copolymer having been formed in and not separated from said mixtureand containing from 70 to 100% of the original polymerizable monomers insaid mixture, with (3) from 60 to parts by weight of a monomer mixtureconsisting of from 85.0 to 99.5% by weight of acrylonitrile and from15.0 to 0.5% by weight of a monomer represented by the above generalformula, until at least 70% by weight of the monomers originally presentin said reaction mixture have combined with said copolymer to give agraft copolymer containing from 60 to 95 by weight of combinedacrylonitrile.

2. A resinous fiber-forming graft copolymer containing from 60 to 95 byweight of combined acrylonitrile obtained according to the process ofclaim 1.

3. A process for preparing a resinous fiber-forming graft copolymercontaining from 60 to 95 by weight of combined acrylonitrile whichcomprises contacting a polymerization reaction mixture consistingpredominantly of water and containing (1) a peroxide polymerizationcatalyst and (2) from 40 to 5 parts by weight of a copolymer consistingof from 50 to 99% by weight of an amide represented by the followinggeneral formula:

i CH (|]CNRr wherein R and R each represents a member selected from thegroup consisting of a hydrogen atom and an alkyl group of from 1 to 4carbon atoms and R represents a member selected from the groupconsisting of a hydrogen atom and 'a methyl group, and from 50 to 1% byweight of acrylonitrile, and the said copolymer having been formed inand not separated from said mixture and containing from 70 to 100% ofthe original monomeric amide and acrylonitrile in said mixture, with (3)from 60 to 95 parts by weight of a monomer mixture consisting of from85.0 to 99.5% by weight of acrylonitrile and from 15.0 to 0.5% by weightof a monomer represented by the above general formula, until at least70% by weight of the monomers originally present in said reactionmixture have combined with said copolymer to give a graft copolymercontaining from 60 to 95 by weight of combined acrylonitrile.

4. A resinous fiber-forming graft copolymer containing from 60 to 95 byweight of combined acrylonitrile obtained according to the process ofclaim 3.

5. A process for preparing a resinous fiber-forming graft copolymercontaining from 60 to 95% by weight of acrylonitrile which comprisescontacting a polymerization reaction mixture consisting predominantly ofwater and containing (1) a peroxide polymerization catalyst and (2) from40 to 5 parts by weight of a copolymer of from 50 to 99% by weight ofN-methyl methacrylamide and 50 to 1% by weight of acrylonitrile formedin and not separated from said mixture and containing from 70 to 100% ofthe monomeric N-methyl methacrylamide and acrylonitrile originallypresent in said mixture, with (3) from 60 to 95 parts by weight of amonomer mixture consisting of from 85.0 to 99.5 by weight ofacrylonitrile and from 15.0 to 0.5% by weight of N-methylmethacrylamide, until at least 70% by weight of the monomers originallypresent in said reaction mixture have combined with said copolymer togive a graft copolymer containing from 60 to 95% by weight of combinedacrylonitrile.

6. A resinous fiber-forming graft copolymer containing from 60 to 95% byweight of combined acrylonitrile obtained according to the process ofclaim 5.

7. A process for preparing a resinous fiber-forming graft copolymercontaining from 60 to 95% by weight of acrylonitrile which comprisescontacting a polymerization reaction mixture consisting predominantly ofwater and containing (1) a peroxide polymerization catalyst and (2) from40 to parts by weight of a copolymer of from 50 to 99% by weight ofN-isopropylacrylamide and 50 to 1% by weight N-methyl methacrylamideformed in and not separated from said mixture and containing from 70 to100% of the monomeric N-isopropylacrylamide and N-methyl methacrylamideoriginally present in said mixture, with (3) from 60 to 95 parts byweight of a monomer mixture consisting of from 85.0 to 99.5% by weightof acrylonitrile and from 15.0 to 0.5% by weight of N-isopropylacrylamide until at least 70% by weight of the monomersoriginally present in said reaction mixture have combined with saidcopolymer to give a graft copolymer containing from 60 to 95% by weightof combined acrylonitrile.

8. A resinous fiber-forming graft copolymer containing from 60 to 95% byweight of combined acrylonitrile obtained according to the process ofclaim 7.

9. A process for preparing a resinous fiber-forming graft copolymercontaining from 60 to 95% by weight of acrylonitrile which comprisescontacting a polymerization reaction mixture consisting predominantly ofwater and containing 1) a peroxide polymerization catalyst and (2) from40 to 5 parts by weight of a copolymer of from 50 to 99% by weight ofmethacrylamide and from 50 to 1% by weight of N,N-dimethylacrylamideformed in and not separated from said mixture and containing from 70 to100% of the monomeric methacrylamide and N,N-dimethylacrylamideoriginally present in said mixture, with (3) from 60 to 95 parts byweight of a monomer mixture consisting of from 85.0 to 99.5 by weight ofacrylonitrile and from 15.0 to 0.5 by weight of methacrylamide until atleast 70% by weight of the monomers originally present in said reactionmixture have combined with said copolymer to give a graft copolymercontaining from 60 to 95% by weight of combined acrylonitrile.

10. A resinous fiber-forming graft copolymer containing from 60 to 95%by Weight of combined acrylonitrile obtained according to the process ofclaim 9.

11. A process for preparing a resinous fiber-forming graft copolymercontaining from 60 to 95% by weight of acrylonitrile which comprisescontacting a polymerization reaction mixture consisting predominantly ofwater and containing 1) a peroxide polymerization catalyst and (2) from40 to 5 parts by weight of a copolymer of from to 99% by weight ofN-methyl methacrylamide and from 50 to 1% by weight ofN-tert-butylacrylamide formed in and not separated from said mixture andcontaining from 70 to 100% of the monomeric N-methyl methacrylamide andfrom 50 to 1% by weight of N- tert-butylacrylamide originally present insaid mixture, with (3) from to 95 parts by weight of a monomer mixtureconsisting of from 85.0 to 99.5 by weight of acrylonitrile and from 15.0to 0.5% by weight of N- methyl methacrylamide, until at least by Weightof the monomers originally present in said reaction mixture havecombined with said copolymer to give a graft copolymer containing from60 to by weight of combined acrylonitrile.

12. A resinous fiber-forming graft copolymer containing from 60 to 95 byweight of combined acrylonitrile obtained according to the process ofclaim 11.

References Cited in the file of this patent UNITED STATES PATENTS2,123,599 Fikentscher et a1 July 12, 1938 2,486,241 Arnold Oct. 25, 19492,649,434 Coover et al. Aug. 18, 1953 2,657,191 Coover et al Oct. 27,1953 2,666,025 Nozaki Ian. 12, 1954 2,666,042 Nozaki Jan. 12, 19542,735,830 Coover Feb. 21, 1956 2,749,325 Craig June 5, 1956 FOREIGNPATENTS 679,562 Great Britain Sept. 17, 1952 999,594 France Oct. 3, 1951

1. A PROCESS FOR PREPARING A RESINOUS FIBER-FORMING GRAFT COPOLYMERCONTAINING FROM 60 TO 95% BY WEIGHT OF COMBINED ACRYLONITRILE WHICHCOMPRISES CONTACTING A POLYMERIZATION REACTION MIXTURE CONSISTINGPREDOMINANTLY OF WATER AND CONTAINING (1) A PERIOXIDE POLYMERIZATIONCATALYST AND (2) FROM 40 TO 5 PARTS BY WEIGHT OF A COPOLYMER CONSISTINGOF FROM 50 TO 99% BY WEIGHT OF AN AMIDE REPRESENTED BY THE FOLLOWINGGENERAL FORMULA: